Scientists using the Hubble Space Telescope found Ceres was more like a planet than an asteroid -- information that eventually led to a change in its categorization from asteroid to dwarf planet.

Ceres' mantle, which wraps around the asteroid's core, may even be composed of water ice. The observations by NASA's Hubble Space Telescope also show that the asteroid has a nearly round shape like Earth's and may have a rocky inner core and a thin, dusty outer crust.